JPH11315164A - Cellulose-based crosslinked complex and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a porous crosslinked complex manufactured easily, having suppressed deterioration of strength and useful as a porous cellulosic immobilized support and a porous cellulosic ion-exchanger applying to immobilization of microbe, wastewater treatment or the like. SOLUTION: This complex is obtained by crosslinking a polymer having a functional group such as cellulose, a cellulose derivative, polyvinyl alcohol or the like. The above functional group is selected from the groups of hydroxyl, carbonyl, amino, amide, carboxyl, ester, cyano and alkenyl and the polymer having a functional group is preferably polyvinyl alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinked composite containing cellulose or a cellulose derivative as one component, a method for producing the same, and a porous cellulose-based immobilization carrier and an ion exchanger formed from the composite crosslinked product. .

[0002]

2. Description of the Related Art Since cellulose has biodegradability, it has the advantage of being decomposed even after being used, but has the problem that it is biodegraded in a short period of time during use. Therefore, the decomposition time is extended by subjecting cellulose to a crosslinking treatment or derivatization.

However, the carrier obtained by this method is
Biodegradation is not completely deterred. Therefore, in applications where the strength of the carrier is required, such as for immobilizing microorganisms for wastewater treatment, the strength will decrease as biodegradation proceeds. As a result, the shape of the carrier cannot be maintained before it is completely biodegraded, and the carrier cannot be used.

On the other hand, a sponge obtained by acetalizing a hydrophilic polyvinyl alcohol is known as a carrier having sufficient strength.

[0005]

However, the production of this polyvinyl alcohol sponge has the disadvantage that a large amount of a porogen such as starch must be used. Further, the acetalization reaction has a disadvantage that it requires a long time (see Japanese Patent Application Laid-Open No. 5-69495). Furthermore, when it is used as a carrier, it has a drawback that it must be cut into a cubic shape having a predetermined size after being formed into a sheet or block.

Accordingly, the present invention seeks to obtain a material that can be easily manufactured and that has a reduced strength.

[0007]

The present invention has solved the above-mentioned problems by obtaining a cellulose composite crosslinked product obtained by crosslinking cellulose or a cellulose derivative and a polymer compound having a functional group with a crosslinking agent. Things.

[0008] The strength of the crosslinked cellulose composite is improved by the polymer compound as compared with the case of using cellulose alone.
In addition, since the biodegradation rate of cellulose or a cellulose derivative can be reduced, the strength of the crosslinked cellulose composite is maintained for a long time.

On the other hand, since the cellulose composite crosslinked product is obtained by crosslinking cellulose and a polymer compound, the hydrophilicity of cellulose or a cellulose derivative and the affinity with microorganisms can be maintained for a long time.

[0010]

Embodiments of the present invention will be described below.

The crosslinked cellulose composite according to the present invention can be obtained by crosslinking cellulose or a cellulose derivative with a polymer compound having a functional group using a crosslinking agent.

The above-mentioned cellulose or cellulose derivative includes cellulose, cellulose xanthate, cuprammonium cellulose, cellulose acetate, methylcellulose, carboxymethylcellulose and the like.

The high molecular compound having a functional group is as follows:
It refers to a polymer compound having a functional group capable of reacting with a crosslinking agent described below. Examples of this functional group include a hydroxyl group, a carbonyl group, an amino group, an imino group, an amide group, a carboxyl group, an ester group, a cyano group, an alkenyl group and the like. The above-mentioned polymer compound may be any as long as it exhibits a predetermined strength when formed into a crosslinked cellulose composite, and may be hydrophilic or hydrophobic. When a hydrophilic polymer compound is used, the obtained cellulose composite cross-linked product becomes a uniform cross-linked product, and when a hydrophobic polymer compound is used, the obtained cellulose composite cross-linked product is a polymer or a cellulose derivative. It becomes a crosslinked body uniformly dispersed therein.

Examples of the hydrophilic polymer compound include polyvinyl alcohol (hereinafter abbreviated as "PVA"), polyethylene glycol, polyvinyl acetate, polyacrylic acid, polyethylene imine, polyallylamine and the like. Examples of the hydrophobic polymer compound include a copolymer of polyethylene, polypropylene, polyester, or the like with a polymer compound having the above functional group, or a compound into which the above functional group is chemically introduced.

The mixing ratio of the above-mentioned cellulose or cellulose derivative to the polymer compound is 1: 0.1 to 0.
1: 1 is preferred. If the amount of the polymer compound is less than 0.1 times that of cellulose, the strength of the polymer compound may not be sufficiently improved. If the amount of the polymer compound exceeds 10 times that of cellulose, affinity with microorganisms is inhibited.

The above-mentioned crosslinking agent may be used between the above-mentioned cellulose molecule or cellulose derivative molecule and the polymer compound molecule, between the cellulose molecules, between the cellulose derivative molecules, between the cellulose molecule and the cellulose derivative molecule, within the cellulose molecule, or within the cellulose molecule. It crosslinks the inside of the derivative molecule, between the polymer compound molecules, the inside of the polymer compound molecule, and the like.
Examples of the crosslinking agent include an epoxy compound, an aldehyde compound, an N-methylol compound, an active vinyl compound, and the like. Examples of epoxy compounds include compounds having one functional group such as epichlorohydrin and glycidol, ethylene glycol diglycidyl ether, glycerol diglycidyl ether, polyethylene glycol diglycidyl ether, polyethylene glycol polyglycidyl ether, and polyglycerol diglycidyl ether. And polyglycidyl ethers such as diglycidyl ethers having two or more functional groups, such as diglycerol polyglycidyl ether, glycerol triglycidyl ether and propylene glycol diglycidyl ether, and triglycidyl ethers.

Examples of the aldehyde compound include formaldehyde, glutaraldehyde, acetaldehyde, glyoxal and the like.

Examples of N-methylol compounds include dimethylol urea, methylated trimethylol melamine, dimethylol ethylene urea, hexamethylol melamine, dimethylol alkyl triazone, methylated dimethylol uron, dimethylol hydroxyethylene urea, Compounds including melamine-formaldehyde, 5-membered urea, 6-membered urea, uron, and triazone compounds such as dimethylol propylene urea can be mentioned.

Further, examples of the active vinyl compound include allylamide type reagents such as divinyl sulfone, tris (β-sulfatoethyl) sulfonium, divinyl ketone, and acrylamide.

Each of the above crosslinking agents may use only one compound, or two or more compounds may be used in combination.

The amount of the crosslinking agent to be added is preferably from 0.1 to 1000% by weight, more preferably from 5 to 80% by weight, and preferably from 10 to 70% by weight, based on the total weight of the cellulose or the cellulose derivative and the polymer compound. More preferred. 0.1% by weight
If the amount is less, the resulting crosslinked product has low cellulase resistance, which is not preferable. On the other hand, if it is more than 1000% by weight, the degree of cross-linking is too high, and it becomes hard and brittle, which is not preferable.

By performing the above-mentioned cross-linking, it is possible to improve the abrasion resistance, the strength such as the tear strength, and the water resistance of the composite of cellulose or a cellulose derivative and a polymer compound. Further, since the biodegradation resistance is improved, the biodegradation rate of cellulose or a cellulose derivative in the composite can be reduced.

Next, a method for producing the crosslinked cellulose composite will be described.

First, the above-mentioned cellulose or cellulose derivative is dissolved by various methods to produce a solution of cellulose or cellulose derivative. As a method for dissolving this cellulose or cellulose derivative, viscose method,
Although there are a copper ammonia method, an alkali dissolution method, and the like, any method may be used.

Next, a polymer solution in which the above-mentioned polymer compound is dissolved is mixed with the solution of the cellulose or the cellulose derivative. When this polymer compound is hydrophilic,
The polymer solution can be an aqueous polymer solution, and can be uniformly mixed with a solution of cellulose or a cellulose derivative. When the polymer compound having a functional group is hydrophobic, the polymer solution is mixed with a solution of cellulose or a cellulose derivative by using a surfactant in an emulsion state.

The above mixture is mixed with the above-mentioned crosslinking agent and molded into a predetermined shape. Since the molded body is easily deformed, it is immediately immersed in a coagulation or coagulation / regeneration liquid to perform coagulation or coagulation / regeneration. If necessary, a porogen such as calcium carbonate, starch, and sodium sulfate may be added to this mixture. This porous agent makes it possible to obtain a porous crosslinked cellulose composite.

Further, the above-mentioned mixture is added with the above-mentioned porogen to form a predetermined shape, immediately immersed in a coagulating or coagulating / regenerating liquid to coagulate or coagulate / regenerate, and thereafter, a crosslinking agent is reacted. Is also good. In this case, if the obtained solidified or coagulated / regenerated body is porous, it can be easily impregnated with a crosslinking agent, and can be easily crosslinked even after solidification or coagulated / regenerated.

Examples of the coagulating or coagulating / regenerating liquid include aqueous solutions of acids such as hydrochloric acid, sulfuric acid and boric acid, sodium sulfate,
Examples include aqueous solutions of salts such as sodium chloride and sodium borate.

Examples of the forming method include a method of forming a spherical shape by dropping from a nozzle, a method of extruding from a die and forming a sheet, and the like.

The shape of the crosslinked cellulose composite obtained by the above-mentioned molding is not particularly limited, and may be, for example, a sphere, a cylinder, a strand, a sheet, or the like.
Sponge-like or the like can be raised.

When the strength of the crosslinked cellulose composite obtained by the above method is insufficient, fibers may be blended at the time of mixing. Examples of the fibers include natural fibers such as hemp fibers and cotton fibers, and synthetic fibers such as fibers made of polyester, polyethylene, polypropylene, and polyvinyl alcohol. The fiber length of this fiber is preferably 0.1 to 10 mm, and more preferably 0.2 to 5 mm. When the fiber length is shorter than 0.1 mm, the strength of the obtained cellulose composite crosslinked product may not be increased. On the other hand, if the length is longer than 10 mm, it may be difficult to produce the cellulose composite crosslinked product.

The amount of the fibers in the above-mentioned crosslinked cellulose composite is such that the amount of the fibers relative to the cellulose or the cellulose derivative is 0.
It is preferably from 01 to 5 times, more preferably from 0.05 to 3 times. 0.0
If the ratio is less than 1, the strength of the obtained crosslinked cellulose composite may not be increased. If it is more than 5 times, the production of the crosslinked cellulose composite may become difficult to produce.

The porous crosslinked cellulose composite obtained by the present invention can be used for various applications.
In particular, since the main component of this crosslinked product is hydrophilic cellulose or a cellulose derivative, it has good affinity with microorganisms,
The amount of microorganisms attached also increases. Therefore, the crosslinked porous cellulose composite according to the present invention can be used as a porous cellulose-based immobilization carrier for immobilizing microorganisms.

It is also possible to introduce a cationic group or an anionic group by reacting a cationic group-containing compound or an anionic group-containing compound with the above-mentioned porous cellulose-based immobilizing carrier, thereby imparting ion exchange ability. it can. As the cationic group, a primary amino group, a secondary amino group,
Examples include a tertiary amino group and a quaternary amino group. Examples of the anionic group include a carboxyl group and a sulfonic acid group.

As a method of reacting the compound having a group having an ion exchange ability, a method of adding the compound before coagulation or coagulation / regeneration of the above-mentioned cellulose composite crosslinked product, or a method of adding the compound crosslinked after coagulation or coagulation / regeneration to the above composite crosslinked product Any method may be used for reacting a compound having a group having ion exchange ability.

[0036]

EXAMPLES The above-mentioned invention will be specifically described with reference to examples. First, a method for producing a composite of cellulose and a polymer compound will be described below.

[Production Example 1] Production of spherical particles composed of regenerated cellulose and PVA PVA was added to 105 g of viscose (cellulose content: 9.5%).
91 g of an aqueous solution (containing 11.0% PVA) and 40 g of calcium carbonate were added. 200 g of this mixture from the nozzle
/ L sodium chloride in 2N aqueous hydrochloric acid. By washing with water and drying, spherical particles were obtained. The yield was 18 g and the bulk specific gravity was 0.08 g / ml.

Production Example 2 Production of Spherical Particles Consisting of Regenerated Cellulose, PVA and PVA Fiber PVA was added to 105 g of viscose (cellulose content: 9.5%).
91 g of aqueous solution (containing 11.0% PVA), PVA fiber 1
0 g (fiber length 2 mm, 0.5 d), calcium carbonate 40
g was added. This mixture was dropped from a nozzle into a 2N aqueous hydrochloric acid solution containing 200 g / l sodium chloride. By washing with water and drying, spherical particles were obtained. Yield 28
g and bulk specific gravity were 0.08 g / ml.

Production Example 3 Production of Regenerated Cellulose Particles To 105 g of viscose (cellulose content: 9.5%), 30 g of calcium carbonate was added. This mixed solution is passed through the nozzle 2
It was added dropwise to a 2N aqueous hydrochloric acid solution containing 00 g / l sodium chloride. By washing with water and drying, spherical particles were obtained. The yield was 9.5 g and the bulk specific gravity was 0.08 g / ml.

[Production Example 4] Production of spherical particles composed of regenerated cellulose and cellulose fibers 105 g of viscose (9.5% of cellulose content), 10 g of hemp fiber (fiber length 2 mm, 3d), and 30 g of calcium carbonate
Was added. The mixture was dropped from a nozzle into a 2N aqueous hydrochloric acid solution containing 200 g / l. By washing with water and drying, spherical particles were obtained. The yield was 19 g and the bulk specific gravity was 0.08 g / ml.

[Example 1] Regenerated cellulose-PVA-
Production of Formaldehyde Composite Cross-Linked Particles 10 g (in terms of dry weight) of the spherical particles before washing with water obtained in Production Example 1 were immersed in a 2N hydrochloric acid aqueous solution containing 10% formaldehyde. After 3 hours, wash and dry with water, cellulose-PV
11.5 g of the A composite crosslinked particles was obtained. The composite crosslinked particles were tested for strength and durability in activated sludge by the following methods. Table 1 shows the results.

Strength test Water 4 was placed in a 1-liter beaker equipped with stainless stirring blades.
00 ml and 50 ml of the particles were added, and the mixture was continuously stirred at 700 rpm for 240 hours. After 240 hours, the residual ratio was calculated by measuring the number of particles retaining the shape.

Durability test The particles were immersed in activated sludge (activated sludge for wastewater treatment at a paper mill of Rengo Co., Ltd.) for 3 months. Three months later, the residual ratio was calculated by measuring the weight.

Example 2 Regenerated Cellulose-PVA-
Production of crosslinked EGD composite particles 3 g of ethylene glycol diglycidyl ether (hereinafter abbreviated as “EGD”) was dissolved in 10 g (dry weight equivalent) of the spherical particles before drying obtained in Production Example 1 and 0.5% hydroxylation. 10 g of a sodium aqueous solution was impregnated, and a crosslinking reaction was performed at 60 ° C. for 3 hours. After the reaction, the resultant was washed with water and dried to obtain 11.5 g of cellulose-PVA-EGD composite crosslinked particles. The strength and durability test in the activated sludge of the composite crosslinked particles were performed by the above-described methods. Table 1 shows the results.

Example 3 Production of Regenerated Cellulose Anion Exchanger PVA was added to 105 g of viscose (cellulose content: 9.5%).
Aqueous solution 91 g (containing 11.0% PVA), 10% polyethyleneimine (hereinafter abbreviated as “PEI”) aqueous solution 1
0 g and 40 g of calcium carbonate were added. This mixed solution was passed through a nozzle through 2N containing 200 g / l sodium chloride.
It was dropped into aqueous hydrochloric acid. The obtained spherical particles were immersed in a 2N aqueous hydrochloric acid solution containing 10% formaldehyde. After 3 hours, the product was washed with water and dried to obtain 24 g of cellulose-PVA-PEI composite crosslinked particles. The durability test of the composite crosslinked particles in activated sludge was performed by the above method. Table 1 shows the results. The particles had an anion exchange ability.

Example 4 Production of Regenerated Cellulose Anion Exchanger 11.5 g of the composite crosslinked particles obtained in Example 2 was added to 2-diethylaminoethyl chloride hydrochloride (hereinafter referred to as “DEAE”).
Abbreviated. ) Impregnated with an aqueous solution containing 0.5 g,
The reaction was performed for 1 hour. After completion of the reaction, the resultant was washed with water and dried to obtain 11.7 g of cellulose-PVA-DEAE composite crosslinked particles. The durability test of the composite crosslinked particles in activated sludge was performed by the above method. Table 1 shows the results. The particles had an anion exchange ability.

[Comparative Examples 1 to 4] The strength and durability test in activated sludge of the particles obtained in Production Examples 1 to 4 were performed by the above-described methods. Table 1 shows the results.

Comparative Example 5 10 g of the particles obtained in Production Example 4 before washing with water were immersed in a 2N aqueous hydrochloric acid solution containing 10% formaldehyde. After 3 hours, the product was washed with water and dried to obtain 10.5 g of crosslinked cellulose particles. The strength and durability test in the activated sludge of the composite crosslinked particles were performed by the above-described methods. Table 1 shows the results.

Comparative Example 6 10 g of the particles obtained in Preparation Example 4 before washing with water were impregnated with 10 g of a 0.5% aqueous sodium hydroxide solution in which 3 g of EGD was dissolved, and a crosslinking reaction was carried out at 60 ° C. for 3 hours. After the reaction, the mixture was washed with water and dried to obtain 10.5 g of crosslinked cellulose particles. The strength and durability test in the activated sludge of the composite crosslinked particles were performed by the above-described methods. Table 1 shows the results.

[0050]

[Table 1]

[0051]

According to the present invention, since the cellulose or the cellulose derivative is chemically bonded to the polymer compound by crosslinking, even if the biodegradation of the cellulose portion or the cellulose derivative portion proceeds, the cellulose composite crosslinked product itself can be used. And the cellulose composite crosslinked body having improved strength as compared with the case of using cellulose alone or cellulose derivative alone can be obtained. Therefore, although decomposed in water by long-term use, for a predetermined period,
A composite crosslinked product having a certain strength can be obtained.

Further, the porous cellulose composite crosslinked product can be used as a porous cellulose-based immobilized carrier or a porous cellulose-based ion exchanger. These carriers and ion exchangers can be used for immobilizing microorganisms, treating wastewater, and the like.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08G 59/22 C08G 59/22 59/62 59/62 C12N 11/12 C12N 11/12 (C08L 1/00 29:04) ( 72) Inventor Wang Onaka 1-8-10 Jiyugaoka, Kanatsu-machi, Sakai-gun, Fukui Prefecture Rengo Co., Ltd. Fukui Research Laboratory

Claims (7)

[Claims] 1. A crosslinked cellulose composite obtained by crosslinking cellulose or a cellulose derivative and a polymer compound having a functional group with a crosslinking agent. 2. The method according to claim 1, wherein the functional group is a hydroxyl group, a carbonyl group,
2. A compound selected from an amino group, an imino group, an amide group, a carboxyl group, an ester group, a cyano group, and an alkenyl group.
3. The crosslinked cellulose composite according to item 1. 3. The crosslinked cellulose composite according to claim 1, wherein the polymer compound having a functional group is polyvinyl alcohol. 4. A cellulose composite crosslink comprising uniformly mixing a solution of cellulose or a cellulose derivative and a solution of a polymer compound having a functional group, adding a crosslinking agent to the mixture, molding, and then coagulating or coagulating / regenerating. How to make the body. 5. A solution of cellulose or a cellulose derivative and a solution of a polymer compound having a functional group are uniformly mixed, and the mixture is molded and solidified or solidified and regenerated.
Next, a method for producing a crosslinked cellulose composite, which is obtained by reacting a crosslinking agent. 6. A porous cellulose-based immobilized carrier comprising the crosslinked cellulose composite according to claim 1, which has porosity. 7. A porous cellulose-based ion exchanger obtained by imparting ion-exchange ability to the porous cellulose-based immobilized carrier according to claim 6.